Dust inhibiting watch crown



June 19, 1951 Patented June 19, 1951 DUST INHIBITIN G WATCH CROWN Joseph Waldman, Maplewood, N. J., assignor to Joseph Waldman & Sons, Irvington, N. J., a firm Application February 5, 1949, Serial No. 74,780

1 Claim. 1

This invention relates to improvements in watch crowns, and has reference, more particularly, to the provision of means in combination with a watch crown which serves to inhibit the entrance of dust through the watch crown stem admission opening of a watch case with which the watch crown is operatively assembled.

The invention has for an object to provide, in combination with a watch crown, a novel construction of dust inhibiting means of such form and relation to the watch crown and to the watch case with which the crown is assembled as to impose a plurality of barriers against entrance of dust past the watch crown and through the crown stem admission opening of the watch case, when the crown occupies its normal main spring winding position relative to the watch case; means being provided to maintain the dust inhibiting means in non-separable assembled, relation to the crown; and means being also provided for maintaining the dust inhibiting means in barrier forming relation to the watch case and its crown stem admission opening.

An illustrative embodiment of the invention is :shown in the accompanying drawings, in which:

Fig. l is a transverse vertical sectional view of a watch crown provided with the dust inhibiting means of this invention, said crown being shown in the normal position occupied thereby for both main spring windings and during running of the watch; Fig. 2 is a similar view, but showing the crown pulled out to connect it with the hand setting mechanism of the watch; Fig. 3 is a horizontal sectional view, taken on line 33 in Fig. 1; and Fig. 4 is a bottom plan view of the watch crown and dust inhibiting means assembly.

Similar characters of reference are employed in the above described views, to indicate corresponding parts.

Referring to the drawings, the reference character I indicates a suitably shaped crown body having a downwardly projecting, axially extending shank ll. Said shank l l is provided with an internally screw-threaded axially aligned socket I2 which enters thereinto from its bottom free end, and into which is adapted to be screwed a winding and setting stem (not shown), whereby the crown may be utilized to manipulate said stem, under proper conditions, for watch winding and setting purposes. The crown body I0 is provided with a downwardly open annular recess or chamber I3 about and concentric to the shank ll.

The reference character indicates an ann l lar barrier element having a central opening [5 which is sized to fit and slidably pass the shank ll of the crown 10 when the barrier element is entered in the recess or chamber I3 of said crown. The barrier element it is provided with an external side wall 58, and is so sized diametrically that said side wall I5 thereof will snugly fit but freely slidably engage the internal side wall I! of the recess or chamber 1 3 in the crown, when said barrier element is entered into the latter. The barrier element M is provided with a fiat bottom is which is adapted to abut the external surface of a watch case wall l9, when the crown is operatively related to the watch case.

Connected with the barrier element l4, preferably as an integral part thereof, so as to depend axially from its bottom I8, is an annular barrier sleeve 20 which is disposed concentric to the axis of the crown l8 and its shank i I. Said barrier sleeve 26 possesses an external diameter which sizes the same to enter the stern admission opening 2! with which the wall is of the watch case is provided, and said barrier sleeve is of a length substantially corresponding to the thickness of said watch case wall [9. The internal diameter of the barrier sleeve 28 exceeds the external diameter of the shank ll of crown [0, whereby to provide an intermediate annular space 22 which terminates at its upper end at the bottom of the barrier element [4, thus providing the latter with an internal stop shoulder 23. Formed on and at the free end of the shank l l of the crown is an external annular stop bead 24, which, by engagement with the stop shoulder 23, both limits outward movement of the crown l9 relative to the barrier element 54, and also serves to retain these parts together in unitary assemblage.

Entering into the central portion of the barrier element M from the top thereof is a countersunk annular seating socket is which surrounds and is concentric to the shank ii of the crown. Mounted about said shank H between the crown l0 and the barrier element Hi is a helical compression spring 26, the lower end of which is footed within the seating socket 25 of said barrier element. Said spring 26 exerts a down thrusting tensional pressure upon the barrier element M which operates to hold the latter constantly abutted against thewatch case wall l9, no matter what the relative position of the crown ID may be, i. e. both when the crown is pulled out to watch setting position as well as when inwardly moved to normal watch winding and running position.

When the watch crown is disposed in the in wardly moved normal position, which it occupies during running of the watch and for use in main spring winding, the most direct path of dust and dirt infiltration to the stem admission opening 2| of the watch case is externally of the crown, i. e. between the bottom of the crown and the watch case wall I9. When the crown is equipped with the dust inhibiting means of this invention,

the barrier element IA obstructs such external stem admission opening. Inward movement of dust and dirtis further inhibited by the barrier sleeve 25] which enters and is engaged in the stem admission opening 2 Sincethe external surface of the barrier sleeve 28 is right angular to the bottom surface i8 of the barrier element 14, any infiltrating movement of dust and dirt between the watch case and these parts is therefore by way of a circuitous path which the angularly related surfaces of these parts define, thus further increasing the obstruction to inward movement of dust and dirt with added inhibiting effect.

In the aforesaid inwardly moved normal position of the watch crown, another but indirect path of dust and dirt infiltration is internally of the crown, i. 6. through the hollow interior of the latter. Since, however, the external side wall It of the barrier element I i closely fits and the external side wall ll of the recess or chain.- her It of the crown, such path or" indirect infiltrating movement of dust and dirt is also obstructed by the barrier element l4. To provide an additional barrier against inward movement of dust and dirt through said indirect path by way of the interior of the crown, the compression spring 26 is so dimensioned that, whensaid spring is contracted by inward movement of the crown to the aforesaid normal position thereof, the convolutions of the spring will be closed together one upon another, thus interposing a further obstruction against inward movement of dust and.

dirt byway of the crown interior to the stem admission opening ii of the watch case wall It. By reason of the relatively spaced apart locations of the side wall it of the barrier element- 14 and the spring 2%, any infiltrating movement of dust and dirt by way of said internal path must also follow a circuitous course which further increases obstruotion to inward movement thereof.

From the above description thereof it will be evident that this invention provides, in combination with a watch crown, a novel construction of dust inhibiting means which is char,-

acterized by the facts that it interposes a plurality of barriers to infiltrating movement of dust and dirt, around and through the crown, at several different points, and additionally compels any such movement to follow circuitous paths which further obstruct the movement with increased inhibiting effect.

Having now described my invention, I claim:

A dust inhibiting watch crown comprising. a crown body having a downwardly directed axial shank to which a winding and setting stem is to be connected, said crown body having a downwardly open recess concentric to the shank, a barrier elementaround the shank to fit within the recess of the crown body and with which said crown body isslidably engaged, the barrier element having a flat bottom to abut a watch case around its stem admission opening, an integral sleeve dependent from the barrier element to snugly fit within the stem admission opening of the watch case, said sleeve being of greater internal diameter than the external d1 ameter of said shank to provide annular space therebetween, the barrier element having an in-. ternal annular stop shoulder overhanging the upper end of said space, an external stop bead at the free end of the shank adapted to be slidably moved upwardly within said space into engagement with the stopshoulder whereby to limit outward movement of the crown body relative to the barrier element, a compression spring intermediate the crown body and the barrier element operative to maintain the latter in constant abutting contact with the watch case, said bar.- rier element having a seating socket in its top portion for reception of the compression spring, and said spring being of helical form and of such pitch that its convolutions close together when the crown body is inwardly moved to a normal position relative to the watch case, whereby to provide additional dust barrier protection.

JOSEPH WALDMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,910,078 Wilsdorf May 23, 1933 2,208,419 Greenberg July 16, 1940 2391935 Feurer Feb. 21, 1959 FOREIGN PATENTS .Number Country Date 207,556 Switzerland Feb. 1, 1944) 

